Should siblings agree on accepting support at home before speaking to a parent?

Ideally, yes. If family members present mixed messages, your parent may feel confused, pressured, or tempted to avoid the subject altogether. It helps to talk privately first, share observations, and agree on the main concerns and the kind of support you think could help. That does not mean everyone must say exactly the same thing, but a consistent approach is usually calmer and clearer. It is also useful to decide who has the closest relationship for starting the conversation, as this may be the person your parent is most likely to hear. If there are disagreements in the family, try to keep those away from your parent so the discussion stays focused on their wellbeing.